Method of producing serrated edges



W. G. SHELTON METHOD OF ERODUCING SERRATED EDGES May 30, 1933,

Filed June 5, 1931 BYaQ 4 A TTORNEYS INVENTOR. William G.'Shelfon Patented May so, 1933 UNITED STATES PATENT .orsics T WILLIAM G. SHEL'ION', F BBIDGEPOBT, CQNNEOTIOUT, ASSIGNOB TO REMINGTON ARMS COMPANY, INC, A CORPORATION DELAWARE JI E'IHOD 0F PRODUCING SEBIBATED EDGES Application filed June 8, 1981. Serial No. 541,784.

This invention relates to the manufacture of cutting implements comprising serrated edges, such as various-types of knives, and sections for grain cutting sickles. The edges of these implements comprise a number of comparatively fine, regularly spaced, projecting teeth, such teeth having in the. ast been formed by chiseling or by grin g spaced grooves in the edge of an otherwise 1o finished blade.

The present invention contemplates an improved method of manufacture in accordance with which indentations, separated by ridges which are to form the teeth, are made upon the article forming blank and the blank is subsequently finished and the teeth formed in a fiat grinding operation.

In the drawings:

Fig. 1 is a side elevation of a knife made grooves or indentations have been formed therein near one edge. The section is on a line between teeth, such as line 5-5 of Fig. 6. Fig. 6 is an enlarged fragmentary side elevation of the blank shown in Fig. 5.

Fig. 7 is an enlarged fragmentary top plainview of the blank shown in Flgs. 5 an verse section of the finished blade. Fig.9 is' an enlarged fragmentary side ilevation of the finished blade shown in i 8. l

e blank from which the blade is to be formed, as shown in Fig. 2, is-of substantially rectangular cross-section. In the first operation, one face of this ,blank is flat ground to substantially final shape. The

4 which is inclined to the upper narrow Fig. 8 is an enlarged fragmentary transblank is now bounded transversely by an upper face 2 (Fig. 3) of substantial width, an unground face 3 substantially perpendicular to the upper face 2, and a ground face face 2. In the next operation, a series of indentations or grooves 5 Figs 5, 6 and 7) are formed in the ground ace 4 adjacent to and extending through the face ,2, and deepening and widening towards such face. These grooves are separated by substantially triangular ridges 6, and it is to be noted that while the grooves 5 approach the edge between faces '2 and 3 this edge remains unbroken, as clearly shown in Figs. 6 and 7. While the ooves or indentations 5 may be formed in anydesired manner, the preferred method comprises grinding them by the use of a rinding wheel comprising a number of ri ges spaced in accordance with the desired spacing or pitch of the serrations on the edge of the finished blade.

After the grooves 5 have been formed, the face 3 of the blade is flat ground. until the flat upper face of the ridges 6 are entirely removed and there remain the pointed teeth 8 (Figs. Sand 9), separated b spaces 10 which were the upper portions 0 the indentations 5, and have been'cut throu h the blade by the flat grinding of the ace 3. The blade is now ready for finishing by cleaning and polishing operations. The teeth are preferably formed in groups, separated bygaps'12 (Fig. 1). The above-described method of forming a serrated edge by first forming indentations in one side of a blank and subsequentlygrinding through the opposite side of the blank into such indentations in a flat grinding operation has been found distinctly superior to the method of first grinding both 'sides of the blade to bring it to an edge and subsequently forming serrations %hgrmding'or cutting teeth on such edge. is latter method inevitably. results in burred and irregular teeth. In, the method of the present invention the grooved grinding wheelis used upon a surface which is backed by solid metal, and a clean grinding operation leaving rigid teeth of uns'trained'nietal results. 109

upon the teeth but in damage comprises The a plication of a grooved, wheel to the thin ed to the teeth themselves due toeutting through the thin metal at closely spaced points. These disadvantages and injuries are eliminated when the indentations between the teeth are formedwhile the blank is still of sufiicient thickness to provide a backing of solid metal, which metal is subsequently remo ed in a simple flat' grinding operation in which there is no strain upon the teeth. Further,

the present method permits deeper Serrations to be made, thus incre the efliciency and prolonging the life of the blade.

What I claim is:

1. In the manufacture of knife blades the methodwhich comprises grinding flat one face of a blank, grinding in said flat face and adjacent one edge thereof a plurality of groups of indentations deepening and widening toward said edge and extending toward but not breaking the edge of the' opposite face, and subsequently grinding said opposite face to expose said indentations, thereby forming an edge comprising groups of serrations.

In the manufacture ofedged tools, the method of producing a serrated edge which forming in said ground face adjacentw one v edge thereof a plurality of regularly spaced indentations deepening and widening and having substantially -V- shaped ridgesbetWeen toward said edge them, and subsequently grinding the op osite face of said blank to expose said indbntations whereby said ridges form a serrated ed e.

\ p v WILLIAM G. S ELTON. I

ge of a blade results not only in burrs grinding one face of a blank, 

